[Bob Carriere]

Yep... confirmed.... the are the same and totally different.....

It seems that the C60 and C15a have the same size nuts...... 2 inches across as per Phil's diagram...... how ever.... the C15a castled nut is almost one inch thick...... has no keyway cut in the axle shaft for the washer slot and therefore the washer is smooth inside out and measures 1 13/32 ID and 2 1/4 OD.....

On the C60 the nut is the same size but only half inch thick but two are installed and they all seem to have two fairly thin sheet metal washer that do fit into the Keyway cut on the C60 axle.......

So the brake hub on a C15a is held fast by a cotter pin and the nut is pushing on a solid 1/8 thick plain washer.. on the C60 it is one nut thigthened over the slotted washer over the first nut..... no cotter pin....

In all 3 instances the washer seems to be the large 2 1/2 size and the washers seem a bit smashed up......

I only had a quick look in the field using the headlights of the truck.... and happened to look at axles with the cast hub cap already removed.... we have others to pick from....

For the record the MB C2 is not of much help..... in the parts listings it shows two washers... one against the brake drum...followed by the first nut...followed by the second washer followed by the second nut..... in the examples I saw tonight it seems that both washers were installed between the two nuts......

Curious to understand what could have caused the rotation of the washer with sufficient torque to shear off the tab on the washer..... also how many washers were installed on your axle... one or two and in what sequence....

Question for the better informed....... any idea if the one nut fixing was early models and later cab 13 got improved two nut/washer arrangement..... usually referred to in the manual as .... after job number #####


Time permitting we will pop a few more cast hub caps from assorted axles to see if there is a pattern.......

Boob